Haven't you check the legitimacy of that site before you played?as you are claiming to be long time gambler since experience is the most important thing to this?
we have seen many Sites from the past that has issues and being denied by players?
i hate to say this but you are careless in this matter so expect this to happen.
Hope this will never to you again as your gambling habit will continue without accepting this claims of yours.
To avoid being careless maybe it's mandatory for all gamblers to verify the gambling site before betting. This is very important so we won't be able to loss a lot of money. If we fail we should move on and don't ever ignore those circumstances that had put you into that worst situations. Learning from a bad experiences, always makes us more mature and vigilant on our future decision making.